microblaze: Rename global function heartbeat()

microblaze:allmodconfig complains for some configurations that 'heartbeat'
is redefined as different kind of symbol. This is seen in test compiles
of watchdog drivers, which often use 'heartbeat' as ststic variable.

Since 'heartbeat' is an unfortunate name for a global function,
rename it to microblaze_heartbeat. Also rename the setup function
to microblaze_setup_heartbeat.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

arch/microblaze/kernel/heartbeat.c

@@ -17,7 +17,7 @@
 
 static unsigned int base_addr;
 
-void heartbeat(void)
+void microblaze_heartbeat(void)
 {
 	static unsigned int cnt, period, dist;
 
@@ -42,7 +42,7 @@ void heartbeat(void)
 	}
 }
 
-void setup_heartbeat(void)
+void microblaze_setup_heartbeat(void)
 {
 	struct device_node *gpio = NULL;
 	int *prop;